Macalpinomyces eriachnes (Thüm.) Langdon & Full.


Sorosporium eriachnes Thüm. (as "eriachnis")
Ustilago australis Cooke


Sori in ovaries, ovoid to ellipsoidal, with a short acute tip bearing the rest of the stigma, 3–4 mm long, 2–3 mm wide, covered by a brown peridium composed of the pericarp, permeated by inter- and intracellular hyphae, and a thin internal layer of hyphae producing the spores and sterile cells. Sori filled with a mass of tightly packed spores in which solitary or grouped giant sterile cells are embedded. Spore mass blackish brown, semi-agglutinated, rather easily disintegrating into irregular many-spored groups or solitary spores.

Spores mostly polyhedrally or subpolyhedrally irregular, 10–19 × 8–12 µm, cinnamon-brown; wall c. 1 µm thick, smooth or minutely granular.

Sterile cells globose, subglobose or slightly irregular, large, 18–32 × 11–26 µm, pale yellowish brown, with a thick (up to 5 µm) smooth wall and granular contents.

Spore germination of hibernated spores resulting partly in simple or branched septate hyphae, partly in 2–4-celled basidia, 1–3 per spore, with varying numbers of fusiform basidiospores arising from each cell.

Host family: Poaceae
Host species: Eriachne agrostidea F.Muell.
Eriachne aristidea F.Muell.
Eriachne armitii F.Muell. ex Benth.
Eriachne avenacea R.Br.
Eriachne capillaris R.Br.
Eriachne ciliata R.Br.
Eriachne festucacea F.Muell
Eriachne glabrata (Mayden) Hartley
Eriachne helmsii Domin
Eriachne melicacea F.Muell.
Eriachne mucronata R.Br.
Eriachne obtusa R.Br.
Eriachne pallescens R.Br.
Eriachne pauciflora W.Fitzg.
Eriachne pulchella Domin
Eriachne scleranthoides F.Muell.
Eriachne sulcata Hartley


States & Territories: NSW, NT, QLD, WA


Mueller sent material to both Cooke and Thümen which resulted in two names, Sorosporium eriachnis Thüm. and Ustilago australis Cooke, appearing in the literature in 1878 and 1879, respectively. Macalpinomyces eriachnes has been recorded on many of the approximately 50 Australian species of Eriachne. It is the only smut known to infect that genus.